System for washing red blood cells to reduce hemolysis

ABSTRACT

A system for washing red blood cells, comprising a separator configured to separate a quantity of blood into concentrated red blood cells having a hematocrit of at least 60% and a volume of 150-250 mL, and a supernatant component. The system comprises a flow controller configured to remove the supernatant component to provide an initial red blood cell concentrate; combine 50-500 mL of an additive solution with the red blood cell concentrate to provide an intermediate red blood cell product intended for storage for 42 days or less, wherein the intermediate red blood cell product at the end of storage has an osmolarity value between 202-479 mOsm/L; and wash the intermediate red blood cell product comprising the osmolarity value between 202-479 mOsm/L with a washing solution having an osmolarity value higher than that of the intermediate red blood cell product comprising the osmolarity value between 202-479 mOsm/L.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase application of Int'l App. No.PCT/US16/032301 filed May 13, 2016, which claims the benefit of U.S.Provisional Patent App. No. 62/169,029 filed Jun. 1, 2015, both of whichare expressly incorporated herein by reference in their entireties.

FIELD OF THE DISCLOSURE

The present disclosure is directed to a system for washing red bloodcells, more particularly, to a system for washing red blood cells with awash media having a specific osmolarity value, to reduce hemolysis ofcells.

BACKGROUND

The administration of blood and/or blood components is common in thetreatment of patients suffering from disease or blood loss. Rather thaninfuse whole blood, individual components may be administered to thepatient in need. For example, administration (infusion) of platelets maybe prescribed for cancer patients whose ability to make platelets hasbeen compromised by chemotherapy. Red blood cells may be administered topatients who have suffered a loss of blood, anemia, or other disorders.Infusion of plasma may also be prescribed for therapeutic reasons, andthe harvesting and processing of white blood cells has receivedwidespread interest within the medical community. Thus, it is oftendesirable to separate and collect a blood component, (e.g., red bloodcells, platelets, plasma, white blood cells) from whole blood and thentreat the patient with the specific blood component. The remainingcomponents may be returned to the donor or collected for other uses.

Several factors may be considered in the separation, collection andstorage of blood components for subsequent transfusion. For example, thepresence of white blood cells (e.g., leukocytes) in a blood componentcollected for administration may be undesirable as such leukocytes cantrigger an adverse response in the recipient-patient. As a result, bloodcomponents are often “leukoreduced” prior to transfusion. Also, thepresence of certain antibodies in plasma has been correlated with theoccurrence of TRALI (transfusion-related acute lung injury) in somepatients receiving blood components such as red blood cells.Consequently, while plasma may be present to some degree in transfusiblered blood cells and platelets, it can be desirable to reduce the amountof plasma in the red blood cell or platelet preparation. Also,extracellular components (e.g., K+, IgA, lactate, free hemoglobin, etc.)may be released by the lysis of cells during the collection, storage,and washing process and may be desirable to wash out.

Red blood cells are often stored for long periods of time prior totransfusion. In this case, it is desirable for the environment in whichthe cells are stored to be carefully controlled to optimize and/ormaintain cell properties required for effective transfusion. Forexample, it is usually desirable to limit hemolysis during storage ofthe RBCs or during washing of the RBCs prior to transfusion. Also,stored red blood cell concentrates (RCCs) are commonly washed prior totransfusion to remove undesirable extracellular components from thecells while maintaining the integrity and functionality of the cells, sothat the probability of immunological reaction in patients is decreased.It is an aim of the wash process to maximize removal of undesirableextracellular components while minimizing cell hemolysis and resultingrelease of free hemoglobin into the surrounding plasma.

SUMMARY

According to an exemplary embodiment, the present disclosure is directedto a system for washing red blood cells, comprising a separatorconfigured to separate a quantity of blood into concentrated red bloodcells having a hematocrit of at least 60% and a volume of 150-250 mL,and a supernatant component. The system comprises a flow controller incommunication with the separator. The flow controller is configured toremove the supernatant component to provide an initial red blood cellconcentrate. The flow controller is configured to combine 50-500 mL ofan additive solution with the red blood cell concentrate to provide anintermediate red blood cell product that is intended for storage for aperiod of time of 42 days or less. The intermediate red blood cellproduct at the end of storage has an osmolarity value between 202-479mOsm/L. The flow controller is configured to wash the intermediate redblood cell product comprising the osmolarity value between 202-479mOsm/L with a washing solution having an osmolarity value higher thanthat of the intermediate red blood cell product comprising theosmolarity value between 202-479 mOsm/L.

According to an exemplary embodiment, the present disclosure is directedto a system for washing red blood cells, comprising a separatorconfigured to separate a quantity of blood into concentrated red bloodcells and a supernatant component. The system also comprises a flowcontroller in communication with the separator. The flow controller isconfigured to remove said supernatant component to provide an initialred blood cell concentrate, combine an additive solution with said redblood cell concentrate to provide an intermediate red blood cell productthat is intended for storage for a period of time, and wash theintermediate red blood cell product that has been stored for a period oftime with a washing solution having an osmolarity value higher than thatof the intermediate red blood cell product.

According to an exemplary embodiment, the present disclosure is directedto a system for processing blood cells comprising a flow controllerconfigured to add a selected volume of additive solution to a quantityof blood. The system also comprises a separator in communication withthe flow controller configured to separate the quantity of blood intoconcentrated red blood cells and a supernatant component, wherein thesupernatant component comprises at least plasma and additive solution,and wherein the concentrated red blood cell component comprises redblood cells and a volume of remaining supernatant. The flow controlleris configured to wash the concentrated red blood cell component with awash media comprising an osmolarity value higher than the osmolarityvalue of the concentrated red blood cell component, and removesubstantially all of the wash media and remaining supernatant to providea treated red blood cell concentrate. A percentage of red cells thathave undergone hemolysis during washing and removal of wash media isless than 0.3% of the red cells from the concentrated red blood cellcomponent.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the present embodiments will becomeapparent from the following description, appended claims, and theaccompanying exemplary embodiments shown in the drawings, which arebriefly described below.

FIG. 1 is a flow diagram generally showing a method for providingreadily transfusible red cells, according to an exemplary embodiment;

FIG. 2 is a flow diagram generally showing the methods of a studyconducted to evaluate washing fluid properties, according to anexemplary embodiment;

FIG. 3A is a chart of observed hemolysis levels within a study conductedto evaluate washing fluid properties, according to an exemplaryembodiment;

FIG. 3B is a chart of observed extracellular potassium levels within astudy conducted to evaluate washing fluid properties, according to anexemplary embodiment;

FIG. 4A is a chart listing different osmolarities of different washsolutions and resulting hemolysis of red cells, according to anexemplary embodiment;

FIG. 4B is a graph showing observed hemolysis of RCCs from dilution withsolutions of varied osmolarities, according to an exemplary embodiment;

FIG. 5 is a graph of percentage of induced hemolysis versus supernatantosmolarity, according to an exemplary embodiment; and

FIG. 6 is a processing set which may be employed to provide a red bloodcell product according to the disclosure herein, according to anexemplary embodiment.

DETAILED DESCRIPTION

There are several aspects of the present subject matter which may beembodied separately or together in the devices and systems described andclaimed below. These aspects may be employed alone or in combinationwith other aspects of the subject matter described herein, and thedescription of these aspects together is not intended to preclude theuse of these aspects separately or the claiming of such aspectsseparately or in different combinations as set forth in the claimsappended hereto.

Some embodiments may decrease hemolysis of blood cells during thewashing process and decrease free hemoglobin levels in the bloodproduct.

The systems and methods of the present disclosure may be used toestablish or control the conditions under which red blood cell productsmay be stored and washed before transfusion. Thus, the methods may beused to introduce additive solutions, washing solutions, or reagentsthat may improve the storage and washing properties of the red bloodcells, thereby providing a transfusible red blood cell product.

In one embodiment, a method for providing readily transfusible, redcells disclosed herein (and depicted in FIG. 1) includes providing aquantity of blood at step 201 a, typically in a container. As usedherein, the term “blood” is meant to include unfractionated andtypically anticoagulated whole blood as well as a red blood cellconcentrate that has been previously derived (i.e., separated) fromwhole blood. Thus, for example, the blood may be a packed orconcentrated red blood cells (i.e., red blood cell concentrate) having ahematrocrit of approximately 60%.

Preferably, however, the “blood” is provided as whole blood in acontainer which can be a blood processing, collection or storagecontainer of the type conventionally used in so-called “manual” or“whole blood” processing, or containers such as those used in automatedapheresis. With regard to automated apheresis, the container in whichthe separation of blood or the processing of blood components may occurmay also refer to the chamber of the separation device, such as acentrifuge or spinning membrane. Non-limiting examples of these are theseparation chambers used in the Alyx® separator, Amicus® separator andAutopheresis-C® separator, all made and sold by Fenwal, Inc. of LakeZurich, Ill. Regardless of whether the “blood” is provided asunfractionated whole blood or an already separated-from whole blood redblood cell concentrate, the blood is separated (for the first time orfurther separated, depending on the composition of the starting “blood”)into red blood cell concentrate and plasma, including any residualanticoagulant from the initial draw.

Where the source of blood is whole blood at step 201, a typical volumeof whole blood is approximately 400-500 mL. The blood may be spun atstep 202 to preferably result in a red blood cell concentrate having ahematocrit of preferably at least 90%. Plasma and residual anticoagulantform a supernatant layer, while the volume of the red blood cellconcentrate separated from the supernatant may be approximately 150-250mL. Once the desired volume of the packed red blood cells or red bloodcell concentrate has been obtained, physical separation and removal ofsubstantially all of the supernatant plasma layer (with anticoagulant)from the red blood cells may take place at step 203. Not all of thesupernatant, however, may have been removed and therefore the initialred blood cell concentrate may typically include about 10-30 mL ofremaining supernatant.

With substantially all of the plasma (and anticoagulant) of thesupernatant removed, a selected quantity or volume of additive solutionmay be added at step 204 to the initial red blood cell concentrateremaining in the initial container in which the whole blood (or other“blood”) was provided, or in a separate container. A non-limitingexample of an additive solution is Adsol®, made and sold by Fenwal, Inc.of Lake Zurich, Ill. The volume of additive solution added to theinitial red blood cell concentrate may be anywhere between approximately50-500 mL, with between about 100-300 mL being preferred. The initialred blood cell concentrate that has been combined with the selectedvolume of additive solution is referred to herein as the “intermediate”blood cell product. The intermediate blood cell product preferablyincludes between approximately 150-250 mL, and more preferablyapproximately 200 mL of red blood cells, approximately 10-30 mL of theremaining supernatant and the added volume of additive solution asdescribed above.

The intermediate blood cell product may then be washed immediately(steps 205 a and 205 b) and used and/or stored until use or transfusion.If stored, the period of storage may vary but preferably not over 42days. Whether the wash process takes place immediately or after storage,the wash solution may impact the health of the blood cell product. Inmanual and automated wash processes, it is not uncommon forextracellular components (e.g., K+, IgA, lactate, etc.) to besuccessfully washed out, while free hemoglobin levels in the washedproduct remain more elevated than desired. Typical wash protocolsinvolve steps that include washing an intermediate blood cell productwith one or more washing fluids. The nature of the washing fluid usedmay influence the efficiency with which extracellular components arewashed out while preventing further lysis of red cells and therebyminimizing free hemoglobin levels.

A study was conducted to evaluate washing fluid properties, and it wasfound that washing fluids with an osmolarity greater than that of theintermediate blood cell product produced reduced levels of cell lysisand free hemoglobin while successfully washing away the extracellularcomponents.

In the study, as depicted in FIG. 2, whole blood units (n=13) werecollected into CPD anticoagulant and each separated via traditionalhard-spin centrifugation into plasma and a red cell concentrate (RCC).110 mL of Adsol (containing glucose, mannitol, adenine, sodium chloride,and water) was added to each red cell concentrate to produce anintermediate RCC product, followed by leukoreduction and storage uprightat 4° C. for 42 days. After 42 days, the intermediate RCC product unitswere removed from storage, well-mixed and transferred into 50 mL conicaltubes. Samples of the RCC were then aliquoted into 5 mL polypropylenetubes either undiluted (control) or diluted at a 1:1 volume ratio. Forthose RCC samples that were diluted, they were diluted with one of thefollowing solutions of known-osmolarity: Adsol, phosphate buffer saline(PBS), standard saline solutions (0.7%, 0.9% 1.1%, 1.3% and 1.5%),citrate phosphate dextrose anticoagulant (CPD), and anticoagulantcitrate dextrose formula A (ACD-A). Samples were thoroughly mixed andheld at room temperature for 0, 1, or 4 hours. Supernatants from thesamples were prepared for K+, free hemoglobin, lactate, and totalprotein analysis by double centrifugation at 2600×g for 10 minutes andnormalized to hematocrit.

Turning to FIGS. 3A and 3B, observed hemolysis and extracellularpotassium levels were charted for different hold times and dilutionsolutions. The RCC Dilution Hemolysis chart in FIG. 3A shows that freehemoglobin levels increased above the undiluted control for samplesdiluted 1:1 in both 0.9% saline and PBS solutions, while free hemoglobinlevels remained on par with the undiluted control for samples dilutedwith Adsol. The RCC Dilution Extracellular K+ chart in FIG. 3B showsthat extracellular potassium levels did not significantly increase abovecontrols for any samples measured. Although not charted, total proteinlevels and total lactate levels also did not increase above controls forthe samples measured. Holding for 0, 1, or 4 hours did not exhibitsignificant differences in hemolysis or extracellular component levels.The results of FIGS. 3A and 3B indicate that intermediate RCCs washedwith normal saline or PBS solution may induce hemolysis with acorrespondingly increased level of free hemoglobin, withoutcorresponding increases in extracellular K+, protein, or lactate.

Turning to FIG. 4A, a chart listing the different osmolarities of thedifferent wash solutions is shown. FIG. 4A also lists the percenthemolysis of the red blood cells that results subsequent to washing theintermediate RCC samples with each wash solution. Observed hemolysis ofRCCs from dilution with the solutions of varied osmolarities subsequentto 42 days of RCC storage is also shown in FIG. 4B. FIG. 4B shows thatthe osmolarity of unwashed RCCs that have been stored for 42 days isapproximately 360 mOsm/L and that the osmolarity of a typical washsolution such as PBS or 0.9% saline is approximately 300 mOsm/L. Thenormal curve demonstrates that as the diluted supernatant osmolaritydecreases farther away from that of the intermediate RCCs stored for 42days, hemolysis of the cells increases to yield higher free hemoglobinlevels. It can also be seen from the normal curve and FIG. 4B that RCCsdiluted with wash media of higher osmolarity than that of the storedintermediate RCC sample do not exhibit increases in free hemoglobin.RCCs washed with solutions similar or higher in osmolarity to theintermediate RCC sample may result in washed products with reduced freehemoglobin levels, according to an exemplary embodiment. These resultsare also consistent with FIG. 4A, in which plasma hemoglobin levels dropsignificantly between 0.9% saline to 1.1% saline, which has anosmolarity similar to that of the intermediate RCCs stored for 42 daysin Adsol.

Turning to FIG. 5, percentage of induced hemolysis versus supernatantosmolarity is shown. It can be seen in FIG. 5 that nearly 100% of cellslyse when supernatant osmolarity is zero and cell lysis plateaus whensupernatant osmolarity is approximately 300 mOsm. The osmotic fragilitypoint, defined as the point at which exactly half the cells have lysedis shown in FIG. 5 to be approximately 140 mOsm. A related graph of RBCmechanical strength distribution is shown in the graphical insert ofFIG. 5. The RBC strength distribution graph shows the point of osmoticrupture for a population of RBCs. At 0 mOsm, almost no cells are shownto withstand lysis. Most cells, as indicated by the middle of the curve,are shown to lyse at approximately 140 mOsm. At 300 mOsm, only theweakest cells are shown to lyse.

Subsequent to washing the intermediate RCCs with a suitable wash mediaas described above, the wash media may be separated from the RCCsaccording to known procedures. The resulting isolated RCCs may betransfused to a recipient and may be described as readily transfusible.

A variety of systems may be used to obtain a red blood cell product inaccordance with the present disclosure. For example, FIG. 6 shows anembodiment of a system (processing set) 100 which may be employed toprovide a red blood cell product according to the disclosure herein. Inthis embodiment, this system includes a plurality of interconnectedcontainers in open or openable fluid communication with each other. Asource container 102 contains the blood to be processed and mayinitially not be connected to the remainder of the processing set 100.The containers and tubing defining the various flow paths may be madefrom a suitable plastic material of the type used in the medical field,such as, but not limited to polyvinyl chloride, acrylics, or polyolefin.The materials used for the containers and tubing and, thus, the entireset are/is sterilizable by, but not limited to, autoclaving.

As shown in FIG. 6, processing set 100 may include a plurality ofplastic containers interconnected by tubing segments. Set 100 mayinclude a first container 102 for holding the source of blood such as,but not limited to, whole blood to be processed in accordance with themethod described herein. Source container 102 may have one or moreaccess sites 103, 105, one of which may be adapted for (sterile)connection to fluid circuit 100 at docking site 104. Preferably, sourcecontainers may be attached in a sterile manner by employing steriledocking devices, such as the BioWelder or the SCD IIB Tubing Welder,available in the market. A second access port 105 may also be providedfor extracting fluid from the source container 102.

Set 100 also may include satellite containers 122, 140, and 150.Container 150, initially empty, may receive the final red blood cellproduct. Access sites 134 a, 134 b may be provided to establish flowcommunication with containers 135 a, 135 b containing an additivesolution and/or wash media as described above, while container 140, alsoinitially empty, may receive plasma separated from source blood incontainer 102. The container 102 may be in fluid communication with eachof the other bags through flow paths defined by tubing. Flow throughprocessing set 100 may be controlled by flow controllers such as clamps,frangible connectors, valves or switches.

According to one embodiment for providing a red blood cell product, anautomated separation and wash procedure is described. Blood such as, butnot limited to whole blood or concentrated red cells, may be received bycontainer 102. As noted above, if the blood in container 102 is wholeblood, the volume may typically be between 400-500 mL. The blood may besubjected to a separation step through a spinning membrane separator 101in FIG. 6 to separate the blood into red blood cell concentrate andplasma. To this end, blood from container 102 may be continuously pumpedtoward spinning membrane separator 101. Prior to entering the separator101, the blood may be continuously mixed at connector 126 with a volumeof wash solution from container 135 a or container 135 b. Afterseparation, plasma, supernatant, and wash media may then be filtered toa second container 140. The red blood cell concentrate may be directedout of port 48 into intermediate container 122 and may include about 200ml of red cells and about 10-30 ml of plasma and anticoagulant (e.g.,CPD). The blood may be processed until container 102 is empty. A rinseof the processing set 100 may optionally be performed to ensure allcells in the set 100 are directed to the intermediate container 122.

After the plasma has been expressed from the container and physicallyseparated from red blood cell concentrate (by, for example, an Optipressor other component extractor), a selected volume, approximately 200 mL,of an additive solution of the type described above may be transferredfrom container 135 a or 135 b to the intermediate container 122containing the red blood cell concentrate to form an intermediate redblood cell product. The intermediate red blood cell product may then beplaced in storage or be further processed for immediate use.

Subsequent to the formation of the intermediate red blood cell product(or subsequent to its storage), the intermediate red blood cell productmay be further processed by spinning membrane separation. Theintermediate red blood cell product in intermediate container 122 mayagain be pumped toward the separator 101. Prior to entering theseparator, the intermediate red blood cell product may be continuouslymixed at connector 126 with a volume of wash solution from container 135a or container 135 b. After separation, plasma, supernatant, and washmedia may then be filtered to a second container 140. The resulting redblood cell concentrate may be directed out of port 48 into a finalproduct container 150. Preferably, the intermediate red blood cellproduct is subjected to separation such that the resulting red bloodcell concentrate has a hematocrit of approximately 80%. As a consequenceof further separating the supernatant and residual plasma from theintermediate red blood cell product, the plasma content of the red bloodcell composition may be further reduced. A rinse of the processing set100 may optionally be performed to ensure all cells in the set 100 aredirected to the final product container 150.

Subsequently, a selected volume of a wash media of the type describedabove may be transferred again from container 135 a or 135 b to thefinal product container 150 containing the resulting red blood cellconcentrate. The resulting red blood cell concentrate suspended in washmedia may be further processed by, for example, separating thesupernatant (containing residual plasma, residual additive solution, andthe wash media) from the red blood cell concentrate. The final isolatedRCCs, transferred to container 150, may be transfused to a recipient andmay be described as readily transfusible.

Without limiting the foregoing description, in accordance with oneaspect of the subject matter herein, there is provided a system forwashing red blood cells. A separator is configured to separate aquantity of blood into concentrated red blood cells having a hematocritof at least 60% and a volume of 150-250 mL, and a supernatant component.A flow controller is in communication with the separator. The flowcontroller is configured to remove the supernatant component to providean initial red blood cell concentrate. The flow controller is alsoconfigured to combine 50-500 mL of an additive solution with the redblood cell concentrate to provide an intermediate red blood cell productthat is intended for storage for a period of time of 42 days or less,wherein the intermediate red blood cell product at the end of storagehas an osmolarity value between 202-479 mOsm/L. The intermediate redblood cell product comprising the osmolarity value between 202-479mOsm/L is washed with a washing solution having an osmolarity valuehigher than that of the intermediate red blood cell product comprisingthe osmolarity value between 202-479 mOsm/L.

In accordance with a second aspect which may be used or combined withthe immediately preceding aspect, the additive solution comprisesglucose, mannitol, and adenine.

In accordance with a third aspect which may be used or combined with anyof the preceding aspects, the osmolarity value of the intermediate redblood cell product at the end of storage is 338-369 mOsm/L.

In accordance with a fourth aspect which may be used or combined withany of the first and second aspects, the osmolarity value of theintermediate red blood cell product at the end of storage is 202-294mOsm/L.

In accordance with a fifth aspect which may be used or combined with thefirst aspect, the osmolarity value of the intermediate red blood cellproduct at the end of storage is 392-479 mOsm/L.

In accordance with a sixth aspect, there is provided a system forwashing red blood cells, comprising a separator configured to separate aquantity of blood into concentrated red blood cells and a supernatantcomponent. A flow controller is in communication with the separator. Theflow controller is configured to remove said supernatant component toprovide an initial red blood cell concentrate. An additive solution iscombined with said red blood cell concentrate to provide an intermediatered blood cell product that is intended for storage for a period oftime. The intermediate red blood cell product that has been stored for aperiod of time is washed with a washing solution having an osmolarityvalue higher than that of the intermediate red blood cell product.

In accordance with a seventh aspect which may be used or combined withthe sixth aspect, the quantity of blood is approximately 400-500 mL involume, the intermediate red blood cell product has a hematocrit of atleast 60%, and the volume of additive solution added to the red bloodcell concentrate is between 50 and 500 mL.

In accordance with an eighth aspect which may be used or combined withany of the sixth and seventh aspects, the period of time for storing theintermediate red blood cell product is not greater than 42 days.

In accordance with a ninth aspect which may be used or combined with anyof the sixth through eighth aspects, the step of separating the quantityof blood into concentrated red blood cells and a supernatant componentis performed by at least one of a centrifuge and spinning membrane.

In accordance with a tenth aspect which may be used or combined with anyof the sixth through ninth aspects, extracellular component levelswithin the washed intermediate red blood cell product is substantiallysimilar to the levels within the unwashed intermediate red blood cellproduct.

In accordance with an eleventh aspect which may be used or combined withany of the sixth through tenth aspects, the osmolarity value of theintermediate red blood cell product is 338-369 mOsm/L.

In accordance with a twelfth aspect which may be used or combined withany of the sixth through tenth aspects, the osmolarity value of theintermediate red blood cell product is 202-294 mOsm/L.

In accordance with a thirteenth aspect which may be used or combinedwith any of the sixth through twelfth aspects, the additive solutioncomprises glucose, mannitol, and adenine.

In accordance with a fourteenth aspect, there is provided a system forprocessing blood cells comprising a flow controller configured to add aselected volume of additive solution to a quantity of blood. A separatoris in communication with the flow controller configured to separate thequantity of blood into concentrated red blood cells and a supernatantcomponent. The supernatant component comprises at least plasma andadditive solution, and the concentrated red blood cell componentcomprises red blood cells and a volume of remaining supernatant. Theflow controller is configured to wash the concentrated red blood cellcomponent with a wash media comprising an osmolarity value higher thanthe osmolarity value of the concentrated red blood cell component, andremove substantially all of the wash media and remaining supernatant toprovide a treated red blood cell concentrate. A percentage of red cellsthat have undergone hemolysis during washing and removal of wash mediais less than 0.3% of the red cells from the concentrated red blood cellcomponent.

In accordance with a fifteenth aspect which may be used or combined withthe immediately preceding aspect, the quantity of blood is approximately400-500 mL in volume, the intermediate red blood cell product has ahematocrit of at least 60%, and the volume of additive solution added tothe red blood cell concentrate is between 50 and 500 mL.

In accordance with a sixteenth aspect which may be used or combined withany of the fourteenth and fifteenth aspects, the separation of thequantity of blood into concentrated red blood cells and a supernatantcomponent is performed by at least one of a centrifuge and spinningmembrane.

In accordance with a seventeenth aspect which may be used or combinedwith any of the fourteenth through sixteenth aspects, extracellularcomponent levels within the treated red blood cell concentrate issubstantially similar to the levels within the quantity of blood.

In accordance with an eighteenth aspect which may be used or combinedwith any of the fourteenth through seventeenth aspects, the osmolarityvalue of the concentrated red blood cell component is 338-369 mOsm/L.

In accordance with a nineteenth aspect which may be used or combinedwith any of the fourteenth through seventeenth aspects, the osmolarityvalue of the intermediate red blood cell product is 202-294 mOsm/L.

In accordance with a twentieth aspect which may be used or combined withany of the fourteenth through nineteenth aspects, the additive solutioncomprises glucose, mannitol, and adenine.

The embodiments disclosed herein are for the purpose of providing adescription of the present subject matter, and it is understood that thesubject matter may be embodied in various other forms and combinationsnot shown in detail. Therefore, specific embodiments and featuresdisclosed herein are not to be interpreted as limiting the subjectmatter as defined in the accompanying claims.

1. A system for washing red blood cells, comprising: a separator configured to separate a quantity of blood into concentrated red blood cells having a hematocrit of at least 60% and a volume of 150-250 mL, and a supernatant component; a flow controller in communication with the separator, wherein the flow controller is configured to: remove the supernatant component to provide an initial red blood cell concentrate; combine 50-500 mL of an additive solution with the red blood cell concentrate to provide an intermediate red blood cell product that is intended for storage for a period of time of 42 days or less, wherein the intermediate red blood cell product at the end of storage has an osmolarity value between 202-479 mOsm/L; and wash the intermediate red blood cell product comprising the osmolarity value between 202-479 mOsm/L with a washing solution having an osmolarity value higher than that of the intermediate red blood cell product comprising the osmolarity value between 202-479 mOsm/L.
 2. The system of claim 1, wherein the additive solution comprises glucose, mannitol, and adenine.
 3. The system of claim 1, wherein the osmolarity value of the intermediate red blood cell product at the end of storage is 338-369 mOsm/L.
 4. The system of claim 1, wherein the osmolarity value of the intermediate red blood cell product at the end of storage is 202-294 mOsm/L.
 5. The system of claim 1, wherein the osmolarity value of the intermediate red blood cell product at the end of storage is 392-479 mOsm/L.
 6. A system for washing red blood cells, comprising: a separator configured to separate a quantity of blood into concentrated red blood cells and a supernatant component; a flow controller in communication with the separator, wherein the flow controller is configured to: remove said supernatant component to provide an initial red blood cell concentrate; combine an additive solution with said red blood cell concentrate to provide an intermediate red blood cell product that is intended for storage for a period of time; and wash the intermediate red blood cell product that has been stored for a period of time with a washing solution having an osmolarity value higher than that of the intermediate red blood cell product.
 7. The system of claim 6, wherein the quantity of blood is approximately 400-500 mL in volume, the intermediate red blood cell product has a hematocrit of at least 60%, and the volume of additive solution added to the red blood cell concentrate is between 50 and 500 mL.
 8. The system of claim 6, wherein the period of time for storing the intermediate red blood cell product is not greater than 42 days.
 9. The system of claim 6, wherein the step of separating the quantity of blood into concentrated red blood cells and a supernatant component is performed by at least one of a centrifuge and spinning membrane.
 10. The system of claim 6, wherein extracellular component levels within the washed intermediate red blood cell product is substantially similar to the levels within the unwashed intermediate red blood cell product.
 11. The system of claim 6, wherein the osmolarity value of the intermediate red blood cell product is 338-369 mOsm/L.
 12. The system of claim 6, wherein the osmolarity value of the intermediate red blood cell product is 202-294 mOsm/L.
 13. The system of claim 6, wherein the additive solution comprises glucose, mannitol, and adenine.
 14. A system for processing blood cells comprising: a flow controller configured to add a selected volume of additive solution to a quantity of blood; a separator in communication with the flow controller configured to separate the quantity of blood into concentrated red blood cells and a supernatant component, wherein the supernatant component comprises at least plasma and additive solution, and wherein the concentrated red blood cell component comprises red blood cells and a volume of remaining supernatant; wherein the flow controller is configured to wash the concentrated red blood cell component with a wash media comprising an osmolarity value higher than the osmolarity value of the concentrated red blood cell component, and remove substantially all of the wash media and remaining supernatant to provide a treated red blood cell concentrate; wherein a percentage of red cells that have undergone hemolysis during washing and removal of wash media is less than 0.3% of the red cells from the concentrated red blood cell component.
 15. The system of claim 14, wherein the quantity of blood is approximately 400-500 mL in volume, the intermediate red blood cell product has a hematocrit of at least 60%, and the volume of additive solution added to the red blood cell concentrate is between 50 and 500 mL.
 16. The system of claim 14, wherein the separation of the quantity of blood into concentrated red blood cells and a supernatant component is performed by at least one of a centrifuge and spinning membrane.
 17. The system of claim 14, wherein extracellular component levels within the treated red blood cell concentrate is substantially similar to the levels within the quantity of blood.
 18. The system of claim 14, wherein the osmolarity value of the concentrated red blood cell component is 338-369 mOsm/L.
 19. The system of claim 14, wherein the osmolarity value of the intermediate red blood cell product is 202-294 mOsm/L.
 20. The system of claim 14, wherein the additive solution comprises glucose, mannitol, and adenine. 